Walked out to my 300SE and noticed a puddle of water under it. However, it wasn't something easy like a hose, it was dripping down the oil pan. Here is a picture of the depressing sight.



I'm guessing it's the weep hole, can't see any coolant from above. How long do I have before the bearings eventually seize?

If I do have to replace the water pump, I'll probably do it myself. But reading a lot of the posts on the m103 water pump is scaring the crap out of me. Looks pretty hard.

Don't let it scare you.
Based on mileage and if it has ever been changed or not plan on replacing the tensioner and the tensioner shock. More pia type job than anything to be scared of.

__________________
Jim

no telling.... better change it asap.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

6 hours.

Make sure of the following:

loosen the center bolt on the tensioner FIRST or you will be buying a new tensioner rod...

If you have more than 75,000 miles since the last tensioner replacement, buy one now, else you will be sitting with an unusable car until you get one. When loosening the tensioner, watch the pointer. If it moves back to near the start of the "ramp" cast in the tensioner, you can re-use it. If it doesn't move, or only goes part way back, the tensioner is shot (and yours is very likely dead).

You will have to pull the tensioner shock up with the belt to get it back on, it tends to run out to full extension and makes the belt look too short.

Not a bad job, just messy and long.

You will need a swivel to get the wp off the head and back on. This would be very easy except for the PS pump in the way....

Make sure you fill the engine with coolant and purge the air correctly before driving, else you will fry the engine (I nearly did) -- pour coolant into the reservior until full, the squash the upper rad hose flat with one hand, then crimp the overflow line from the rad to the tank shut with the other. Release the upper rad hose, coolant will be sucked up into the engine. Repeat, filling the tank when it goes dry, until no more coolant gets sucked in. You will still be quite a bit short after a couple heat/cool cycles, but it won't overheat.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Good advise from Jim and PS Fred.

Over the years, there has been a lot of yack here about buying some special Snap-On swivel tool. If you make a living replacing 103 water pumps, go buy it, else just follow the procedure in the 103 engine manual or whichever CD you have(same thing).

As stated above, this might be a good time to change out the tensioner, shock, etc.

This is not a hard job, but it does require removing a lot of pieces and if you're not into that, let someone else do it.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Well I just changed my serp belt a week or two ago, and the tensioner was fine, so I think I'm safe there. I have no problem removing a lot of stuff, I just refinished all the wood in the interior, and remembering where everything goes will probably be easier during the water pump job. Just need to find a mode of back up transportation in case this ends up taking longer then it should. What brand of water pump should I use? I'll probably order from fastlane, looks like there are three different brands.

And I've read about some trouble with converting over to the new WP design? I have a 1990, so I believe it won't be a problem. Don't know if the WP has been replaced before, I'll have to go through the service history. I doubt it has.

I just did a coolant flush recently too, so I won't have to go out and spend $50 at benz. Hooray.

I could not do this job without a 1/4 inch 13mm socket and wobble extension... . it was for the two back bolts, top and bottom.

The socket was inexpensive... I tried for 90 minutes to get the top back bolt with a 3/8 socket but no luck...just not enough room

i opted out of the snap on tool. i think the 13mm cost me 6 dollars.. i had the wobbles

i had to do two of these within weeks of each other....one car needed the tensioner, the other did not. 6 hours is about right. Someone claims they can do one in a couple of hours..but i don't see how.

do yourself a favor and take the radiator out first... it doesn't take very long and it buys you space and piece of mind.

Be careful on the power steering pump... if you pull the wrong bolts.. you will have ps fluid all over the place. Ask me how I know.

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1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]

My W124 300E leaked coolant for a day then stopped for a week before starting again.
My leak was coming from the o-ring between the pump and the block but as the car had done 260000kms, I put a new pump on anyway.
Took me just under 2 hours including a trip to the hardware store for some rubber grease.

__________________
Tony
76 W116 280SE
74 W107 450SLC
88 W124 300E
82 W123 280TE

Not necessary on a 126 car with a 103 motor - 300SE/300SEL.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

I didn't remove the radiator on my 124 either, but I did slide a piece of cardbord down to protect it while working.

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Tony
76 W116 280SE
74 W107 450SLC
88 W124 300E
82 W123 280TE

Ditto - tensioner is easily replaced while you have it out for the H2O pump replacement. They don't cost that much, so you're better off replacing while you're in there already.

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08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280

I am continuing the monitoring of water drips.
So far so good. If it was the O-ring, maybe it had a bad hair day and resumed its duty.

I know that is pipe dream material so everybody's tips will serve me well if and when I end up having the pump replaced with all the other stuff.

Car (1998 300SE) has about 136K miles on it......

Update feb 5-08 had mechanic replace water pump.

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1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD